Adams. — Tit" Wellington Tide-gaiiye. 



409 



so that the pencil draws a second line : the correct local mean time is written 

 on this line, and again no record is made of the time shown on the clock. 

 In fact, the sole purpose of the clock is to give uniform motion to the pencil, 

 and so long as the clock's rate does not materially vary the record will be 

 correct. And at any time during the week a check line can be similarly 

 drawn, and the correct local mean time noted on it. A check on the rate 

 of the clock is obtained by measuring the distance between the end lines 

 on the record. 



Fig. 3 shows a portion of the record of this gauge, beginning 1908, 

 July 11. The first line was drawn at 9.55 a.m., and a check line is shown 

 at 11.45 a.m. The last line (not shown) was drawn on July 18 at 9.20 

 a.m., while other check lines (not shown) were drawn on July 14 at 

 12.40 and 13.00. The lines showing midnight are drawn in by scale from 

 the first and last lines on the diagram. 



^Feet 



Vertical Scale 



Fig. 3. 



Particulars of the Wellington gauge were recently sent to Sir G. H. 

 Darwin, who replied, " I never heard of a tide-gauge such as that you 

 describe, but there seems no reason why it should not work very well." 



Harmonic Tidal Constants. 



Through the courtesy of Mr. Thomas Wright, of " Lyndhurst," Victoria 

 Drive, Eastbourne, Sussex, the harmonic tidal constants for Wellington 

 and Auckland are here recorded. Mr. Wright states, " They have been 

 obtained by the aid of Grovernment grants from the Royal Society, and were 

 deduced by methods devised by Sir G. H. Darwin, and will be presented 

 for publication in the Proceedings of that Society. The constants for Wel- 

 lington were obtained from twelve months' observations, the epoch to which 



